MODULATION DRIVER WIDEBAND POWER DEVELOPMENT PROJECT

调制驱动器宽带电源开发项目

• 批准号: 8363959
• 负责人: CURT R DUNNAM
• 金额: $ 0.05万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8363959
• 关键词: Amplifiers; Automobile Driving; Biology; Chemistry; Clip; Detection; Development; Exhibits; Frequencies; Funding; Generations; Grant; Heating; Hybrids; Laboratories; National Center for Research Resources; Noise; Output; Principal Investigator; Research; Research Infrastructure; Resources; Services; Signal Transduction; Source; Technology; Testing; United States National Institutes of Health; Width; cost; design; electric impedance; magnetic field; millimeter; operation; voltage

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. High-level modulation of the B0 external magnetic field is desirable in millimeter-wave ESR studies over a wide range of problems in chemistry and biology where the linewidths are often large (100G) given that the signal to noise ratio (SNR) is proportional to the modulation amplitude (mod amp) for mod amps less than or approaching 1/5 of the line width. For high-level modulation of B0 in our 170 and 240 GHz spectrometer bridges, we have designed an extremely wideband power amplifier which is capable of stably driving off-tuned resonant loads which exhibit a large reactive component. Conventional audio-frequency power amplifiers, which are sometimes pressed into service as modulation coil drivers, are not well-suited for this type of service. Generally, they are inefficient and poorly characterized in the region above approximately 50 KHz, especially when driving highly capacitive or inductive impedances. The ACERT modulation amplifier design, in contrast, overcomes those limitations. It operates in either constant-current (CC) or constant-voltage (CV) modes, and can produce up to 50 watts of output power at frequencies from d.c. to 150KHz. Utilizing a commercially-available h.v. hybrid operational amplifier, this wideband power driver design is simple, low-cost and robust, but also features high linearity and stability. Its output section includes provisions for detection and signaling of abnormal output conditions, such as clipping due to, e.g., mistuning of the modulation coil network. Operation in CC mode minimizes amplitude drift in the detected spectrum due to modulation coil self-heating and permits direct modulation with a constant magnetic field generation coefficient, when a fixed input-to-field ratio is required. CV mode permits use of the amplifier in other laboratory applications such as piezoelectric actuator driver for CD-ESR. Having prototyped and tested sections of the modulation driver amplifier, our next step in the project plan is to design a compact package for the complete amplifier and construct several integrated units for HF, and possible CD-ESR use, during the coming year.

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 在毫米波ESR研究中，希望对B0外部磁场进行高电平调制，研究范围广泛的化学和生物问题，其中线宽通常很大(100G)，因为对于小于或接近线宽的1/5的mod放大器，信噪比(SNR)与调制幅度(Mod Amp)成正比。为了在我们的170 GHz和240 GHz光谱仪桥中对B0进行高电平调制，我们设计了一种极宽带功率放大器，能够稳定地驱动表现出大无功分量的失谐谐振负载。传统的音频功率放大器有时被用作调制线圈驱动器，不能很好地适应这种类型的服务。一般来说，它们在大约50 kHz以上的区域效率低且特性差，特别是在驱动高电容或电感阻抗时。相比之下，Acert调制放大器设计克服了这些限制。它在恒流(CC)或恒压(CV)模式下工作，在直流频率下可以产生高达50瓦的输出功率。到150千赫。利用一种商业上可用的H.V.混合运算放大器，这种宽带功率驱动器设计简单、低成本和坚固耐用，但还具有高线性度和稳定性。其输出部分包括用于异常输出条件的检测和信号发送的规定，例如由于调制线圈网络的错误调谐而引起的限幅。在CC模式下运行可最大限度地减少由于调制线圈自加热而导致的检测频谱中的幅度漂移，并允许在需要固定的输入与场比时使用恒定磁场产生系数的直接调制。CV模式允许在其他实验室应用中使用该放大器，例如用于CD-ESR的压电驱动器驱动器。在完成调制驱动器放大器的原型和测试部分后，我们在项目计划中的下一步是为整个放大器设计一个紧凑的封装，并在来年为高频和可能的CD-ESR使用建造几个集成单元。